1. Field of the Invention
The present invention relates to image processing apparatuses and methods, and programs, and more particularly, to an image processing apparatus and method, and a program, which are suitably used for personal authentication.
2. Description of the Related Art
Face image authentication in which personal authentication is performed using an image of the face of a person (hereinafter, also referred to as a face image) is known.
In known face image authentication, as shown in FIG. 1, a plurality of face images 11-1 to 11-3 of a person (a registered person) that have been previously captured and recorded in advance are compared with a face image 12 of a person to be identified that is newly captured for face image authentication, and it is determined whether or not the person to be identified is equal to the registered person.
Face image data of the previously captured face images 11-1 to 11-3 and face image data of the newly captured face image 12 are subjected to predetermined conversion processing, and the feature quantities of features of the faces of the persons are extracted from the individual sets of image data. Then, it is determined whether or not the feature quantity extracted from the face image data of the face image 12 is located within an area (hereinafter, referred to as an authentication area), which is constituted by the feature quantities extracted from the face image data of the face images 11-1 to 11-3, in a feature space.
If it is determined that the feature quantity extracted from the face image data of the face image 12 is located within the authentication area, the person to which the newly captured face image 12 belongs is authenticated as the registered person. In contrast, if it is determined that the feature quantity extracted from the face image data of the face image 12 is not located within the authentication area, the person to which the newly captured face image 12 belongs is identified as not being the registered person, and the subsequent processing is thus not carried out.
In addition, for face image authentication, since a plurality of previously captured face images are recorded in advance, the average of the feature quantities of the plurality of face images can be acquired, the average of the face images of a registered person can be estimated, and the width of dispersion of feature quantities can be estimated for each face image. Thus, the accuracy of face image authentication can be further improved.
In addition, an authentication apparatus is available in which statistical data representing general time-lapse changes in regions of faces and image data of a previously captured face image of a registered person are stored in advance and in which authentication is performed by transforming each region of the stored face image of the registered person on the basis of the statistical data (see, for example, Japanese Unexamined Patent Application Publication No. 09-134428). In this authentication apparatus, authentication is performed by comparing the previously captured face image of the registered person that has been transformed on the basis of the statistical data with a face image of a person to be identified newly captured for authentication.